Cutting toolholding means for machine tools



Oct. 12, 1948.

J. A. BACKSTROM CUTTII JG TOOL HOLDING MEANS FOR MACHINE TOOLS Filed July 2a, 1943 3 Sheets-She'et 1 IN V EN TOR.

gm/pm Jew/-14. fifiCKS'TEOM BY flme/vsvs Oct. 12, 1948. J. A. BACKSTROM CUTTING TOOL HOLDING MEANS FOR MACHINE TOOLS S Sheets-$het 2 Filed July 28, 1943 2 INVENTOR.

Bi fOH/Y 14546/(57'50/1 4M ZWZIMM Oct. 12, 1948. J. A. BACKSTROM CUTTING TOOL HOLDING MEANS FOR MACHINE TOOLS Fil'ed m 28, 1943 3 $heets-$heet 5 v Tl 44m) W WWMZMM AIII IT A A a Patented Oct. 12, 1948 'CUTTIN G .TOOLHOLDING MEANS FOR MACHINE TOOLS John A. Backstrom, Euclid, hio,'=assignor =to .T-he Brock Company, a corporationof Ohio Application July 28, 1943, Serial No. 496,458

(Cl. DIP-155) Claims.

This invention relates to an improved and novel cutting .tool holding means for a slotter, planer or other similar type of machine tool wherein the cutting tool or tools ordinarily are moved relatively along, over or across and in contactwith the work during their :idle or rearward strokes.

An object of the invention is to provide a cutting tool holding .means of the character above set forth and which means eliminates damage to and lessens the wear on the cutting tool or tools by automatically moving and maintaining the latter fully out of contact with the work during the idle or non-cutting strokes of the tool or tools relatively along, over or across the work.

Anotherobject is to provide a cutting tool holding means of the character set forth and which means will increase the effective accurate life of the cutting tool or tools carried thereby and will improve the accuracy of the cuts taken in the work by the tool or tools.

A further object is to provide a cutting tool holding means of the kind specified and the use of which obviates repeated and frequent regrindof the tool or tools thereby pIOlOl'lging their useful life and increasing the efiiciency of operation of the machine tool and conserving the time of the operator thereof.

Further and additional objects and advantages of the invention will become apparent hereinafter during the detailed description of embodiments of the invention and which description is to follow. I

The invention contemplates a tool holding means for use in a slotter, planer or similar type of machine tool wherein the cutting tool or'tools move relatively along, over or across and ordinarily in contact with the work during their idle or rearward strokes. The contemplated tool holding means is so constructed and 'so functions that the cutting tool or tools carried thereby are completely and automatically disengaged from the work at the start of and are so held during the idle or non-cutting strokes and then automatically moved to and held in an active or cutting position prior to and during their cutting strokes.

The tool holding means includesa movable element in which the tool or tools are secured and said element is moved automatically from anactive or cutting position to one wherein the tool or tools are in a non-cutting or inactive position and vice versa. The movement of this element can be accomplished by various means as, for example, the element can be moved in both di- 2 rections by power means such as a fluid pressure motor or any-other suitable motor operated from any suitable power source. The movements of the element through the actuation of the motor are automatically controlled by suitable control means as, for example, a-cam control mechanism.

In addition, the element can be moved mechanicaliy or its movement in one direction may be by positive means while its movement in the op- .p'osite direction can be by spring means 'or by gravity or by a combination thereof.

Referring to the accompanying drawings illustrating several embodiments of the invention,

Fig. 1 is a fragmentary side elevational view of a portion of a vertical .slotter to the reciprocatlng ram of which isflsecu'red one form of the improved and novel cutting tool holding means embodying the invention; the work which is clamped on the table of the machine tool being shown in section while "the cutting tools are shown in cutting or active position and prior to their cutting engagement with the work.

Fig. is a fragmentary front elevation-of the sl-otter shown in Fig. '1 and is taken looking from the right hand side of said Fig. 1.

Fig. 3 is a fragmentary sideelevational view of a portion of the slotter shown in Fig. 1 and illustrates the improved cutting tool holding means when the movable element thereof is in its rearward position and the cutting tools carried thereby are in non-cutting or inactive position.

Fig. 4 is a fragmentary transverse verticalsectional view taken substantially on line 4-4 of Fig. 1 looking in the direction of the arrows.

Fig. 5 is a view similar to Fig. 1 but illustrates a difierent form of the invention than that shown in Fig. 1.

Fig. 6 is a fragmentary side elevational view of a portion of the'slotter show-n in Fig. 5 and illustrates the relationship of the parts of the cutting tool holding means when the movable element thereof has been rocked to position the cutting tools in non-cutting or inactive position.

Fig. '7 is a fragmentary sectional view taken substantiallyon line l? of 5 .l'ooki-ng in the direction of the arrows, and

Fig. 8 is a fragmentary transverse vertical sectional and front elevational view taken substantially on line 8-8 of Fig; .5, looking in the-direction of the arrows.

As previously stated, the cutting tool holding means embodying the present invention can be advantageously used in various kinds of machine tools of the general type wherein the cutting tool or tools move relatively along, ever or across and riage equipped with an adjustable and/ or indexi- I ble work supporting table. The carriage is given a feeding movement by suitable mechanism for cutting stroke to cause the cutting tools to cut slots of the required depth as will be well understood. The rings and the work supporting table are indexed by well known mechanism upon'the completion of one slot 2. distance equal to the circular spacing of the slots to cause the cutting tools to cut the successive internal slots in the rings. It 7 will be understood that the cutting tools during. each cutting stroke operate upon all of the vertically stacked rings. Referring to Figs. 1 to 4 inclusive the form of the invention shown therein will now be described.

the purpose of causing the cutting tools to cut 7 slots in the work to the proper depth while the table is adjusted or is indexed on the carriage to bring successive portions of the work into position to be acted on by the cutting tools. At one end of the bed there is a vertical standard which 11 its face adjacent to the work supporting table is provided with a vertically movable or adjustable support and said support carries by means of suitable ways a vertically reciprocating ram that has provision at its lower end for attaching thereto the cutting tool or tools. The adjustment or movement of the support on the standard and the reciprocating movement of the ram are cheated and controlled by suitable well known mechanism which acts to automatically reverse the movement of the ram at the predetermined limits of its cutting stroke and its idle or upward stroke. Inasmuch as the foregoing features of a vertical slotter are well known in the art and per se form no part of the present invention they have not been illustrated herein and will be well understood by anyone skilled in the art.

Referring to the accompanying drawings there shown therein the movable or adjustable support it which is carried by the vertical standard (not shown) of a conventionel vertical slotter. The reciprocating ram l l of the slotter is slidably supported by the support H) in an well known manner. The lower end'of the ram has attached thereto the usual block [2 to which can be secured the cutting tool or tools. tools ordinarily are carried by what is known as a clapper box and which box includes a tool carrying part that has a limited rocking movement such that upon the upward or idle stroke of the ram said part rocks slightly in one direction to relieve the cutting tools and which tools then drag along the workduring said stroke, while upon the active or downward cutting stroke of the ram said part will rock slightly in the opposite direction to bring the tools to cutting position and the cutting action of the tools will hold said part in this rocked position during said'cutting stroke.

The improved and novel cutting tool holding means of the present invention is intended'to be used in place of the ordinary clapper box and in the manner later to be explained.

The work illustrated herein comprises rings l3 in which a plurality of circularly spaced internal slots H5 are to be out. A plurality of the rings are stacked one above the other and clamped in this stacked position on the work supporting table of the machine and the clamped rings are so located that the cutting tool holding means onv The cutting tool or longitudinal sides with the wear plate 11.

A block I5 is secured to the underside of the block 12 which, in turn, is secured to the lower end of the ram and said block l5 moves with the block I! and the ram ll during their reciprocatory movement. The block I5 at its lower end and on opposite sides thereof is provided with laterally extending flanges Hi. The lower face of the block I5 is provided with a recess extendin its full length and secured in said recess is a wear plate I'I. Gibs 18 are secured to the underside of the block l5 and the flanges l6 by suitable securing means such as the screws [9. The inner edges of these gibs are stepped to provide parallel supporting ways .20 extending the full length of the gibs.

A tool carrying member 2| is'slidably supported and guided by the gibs l8 and said member has at its upper end and on the opposite sides thereof longitudinally extending laterally projecting ribs 22 which bear upon and are supported by the ways 20 of the gibs. The top of the member 2| is recessed and engages adjacent its opposite It will be seen that the tool carrying member 2i is firmly supported and guided for sliding movement inwardly and outwardly along the bottom face of the block I5. The outer or right hand end of the member 2| at its upper corners has block portions 23 located at the outer ends of the ribs 22 and which block portions contact the right hand ends of the gibs l8 and limit the movement of the member 2| toward theleft relative-to the block l5 by their engagement with the right hand ends of the gibs 18, as viewed in the drawings. The tool carryingmemberil is provided with a centrally disposed longitudinally extending opening therethrough and in which opening the shanks of one or more cutting tools can be secured and clamped by means of suitable clamp screws 25 as will be well understood in the art. 7

In the present illustration the cutting tools are shown as three in number and comprise a roughing cutter 26, a semi-finishing cutter 21 and a finishing cutter 2-8 arranged one above the other in the inverse order named. Plates 29 are secured to the outer sides of the flanges 16 by suitable securing means and extend downwardly and over the outer sides of the gibs I8. I

The block I5 is cored out and has fixed therein a cylinder 30 extending parallel to the-waysio and provided with a piston 3! from which extends a piston rod 32 that projects outwardly and centrally of the right hand end of the block [5. The outer end of the piston rod has fixed thereto a fork 33 which straddles the upper end of an up wardly projecting arm 34 and is connected to said 7 in the cylinder 30 is transmitted through the pis- V tonrod 32, arm 34 and plate 38 to the member 2! toslide the latter in opposite directions von the lower end of the block l5.

' The piston 3! is moved in opposite directions by means of fluid pressure introduced into the cylinder and which in this instance is..com pressed air although it will be understood that hydraulic pressure could be utilized for the same purpose.

Conduits 31 and aa are connected to the interior of the cylinder 30 at the opposite ends thereof and said conduits extend to a valve mechanism 39. arried by .the ram II, This valve mechanism may be of any well known and suitable form and includes means for selectively connecting one or the other of, the. conduits 3.1 and 3a with. a supply conduit 40 which is connected to the valve mechanism and extends to a source of supply of comp s ed air. The. valve mechanism 391s actuated by a pair-of normally extended plunger-s M and 42 and which plungers areselectivelyactuated to connect their respective conduits. 3:1 or 38 with the upply conduit 4c and to effect. a. venting to atmosphere of the other conduit which is. not connected to the. supply conduit. Thus it will be e n that by depressin one. of: the pioneers; and l owing th normal extension or the other p n pneumatic pressure can. be introduced into he y inder 30 on one side. or the other or the piston 3! whi he interior of the cylinder 30 on the opposite side of. the piston willbe vented t tmospher Consequent y the piston. 3:! c n e pn umat cally moved the cylinder" 38 to th r ne of its two extreme positions therein and c m vem n will; eiizect a. movement of the memb 2. an he t olscarried therebyeither m. th position. shown. in Fi 1-. to its os t n as wn n Fig 3 or viceve sa. as the case may be.

Cam lates 43 and 44 are secured to; the supp 10 n the ront thereof; and adja ent. to t mm H T am plat s. 433 and. 4% are; vertically spac d h respect to each other and are pros vidcd with el gated slot throu h whi h th ir securing bolts extend, thuscnabling the plates to be adjusted verticallyot th support, The positions of these cam plates; determine the points in the u ward and. downward-1 travel of the; ram l l: at which the member 21' is moved; the piston 3 i into active orcutting; position or into inactive or non-cutting position. The upperplate; he so located h the member 22*. and the. tools carried thereby; be. automatically mcvedito active or cutting position-, asshown- Fig. 1 after. the m has moved sufficie t-1v tar upwardly to clear the work and before it commences as downward-or cutting stroke. The plate 44 will; be; so positioned as to effect rearward movement of the mber d. thet ols; carniedzt er v rom, the. position shown inFig, 1' to. therpositionshown. in Fig. 3 at the moment. the downward or cutting stroke of the ram has been completed. 7

i It will be noted that the; cam plates 43 and 44 are angle plates, with the arms: thereof; that; have the cam surfaces formed thereon. ohQ-Qsitelwdi'sr' posed with respect toeacli othen, In-otherwords. thearm of the; cam: plate which has the cam surface thereon is locatedadjacent to thera-m I l, while the corresponding arm of the cam plate 4:4. i located at the outer side of. its. attach-ingarm as clearly shown in Eig,.2. v

h valve mechanism .9i h vctallyccnne thcreto rocker plate 45.- and saidiroclser plate is. provided adjacent its, lower left hand corner, as viewed, inthe d lawingdi, with a pin 46,- pro.-

jecting laterally from the plate land towardthe ram I I and in a position to contact the camsurface of the cam plate 43 when the ram H approaches the limit of its upward movement as illustrated in Figs. 1 and 2. The rocker plate 45 adjacent its. upper left hand corner as viewed in'F-igs. Land 2 is provided with a pin 41 project ing laterally from the side of the plate remote from the ram H and in a position to be acted on by the cam surface of the cam plate 44 whenthe downward or cuttingstroke of the ram H is completed; .When the pin 46 of the rocker plate 45 engages the cam surfaceof the cam plate 43 said rocker plate is rocked in. an anti-clockwise direction and its inner edge contacts the plunger 42 of the valve mechanism 39 and depresses the same, and at this time the plunger ll of said valve mechanism isfully extended. When the pin 41 of therocker late 45 contacts the cam surface or the cam plate 44 said rocker plate is rocked in a clockwise direction and its outer edge. depresses the-plunger 4| of the valve mechanism and. at suchitime the plunger 42 thereof is fully extended.

In order to eliminate. any outward sliding movement of. the member 21 during the. cutting stroke of the ramand under the thrust on the cutting tools carried by said member means is provided for positively holding the. member II: in its inner or cutting position. This means is in the form of a rectangular casing 4K secured to. the block l5 and having a rectangular lock bolt 49 slidable vertically therein and of such length that; when said lock bolt is fully projected a portion or! the lock bolt will extend below the casing 48 andlie in the path of movement. of a portion of the plate 3.6 and thus positively prevent. outward movement. of the plate && and the member it. The lock bolt k9. is maintained in its fully projected or downward position, as shown in Figs; 1 and 2-, by a coil spring 50: located in the casing Ml" betweenthe upper end of the. lockbolt and the inner side of the upper wall of the casing, it being understood thatv suitable means is provided to keep. the bolt from being completelyexpelled from. the casing. A rod 5|. extends downwardly from. the lower end of the. lock bolt 49 and is of such length. that its lower end is located below the lower; end of the member 21.. Just prior to the completing: its downward or cutting stroke the lower end of; the rod 5.l contacts the work supporting; table. and the. further downwardmovement of: the ram H to complete. its cutting stroke. causes; the rod 5t and the, lock, bolt 4.9: to be. moved positivelyupward-ly against the action of the; sprin -5,0; and. until the lock. bolt 49: is completely housed. within. the: easing 48 and; is out of the path of, movement. ct any part of theplate and then the: members it is free. to be moved bythe pneumatic. motor from. its cutting; position as shown Fig. l rearwardlv to its inactive or. non-cutting; position as shown in Fig, 3..

In this connection it will be noted that. the. rod 5-! is positioned at: all times out. of pathoi' movement of. any portion of. the; plate-36. As soon I asithemember 2|. cominences.-its'outer movement toward inactive position. the; upperend of the member. will underlie theilower end -of the. casing 48,- and hold the lock. bolt 43 its. raisedposition. As soon as; the ram II: has reached. its upward limiter movement. and: is; ready; to. commence its downward or cutting; stroke and the; member; 21: has been moved inwardly tocutting; position. the upper end ofisaid member is freeof the locls bolt $6 1. and thelatter. istree to; be; projected. downwardlyebv thesspring; Fin and tohazve its lowehpfl i tion located in the path of movement of the lower left hand part of theplate36'.

.A resume of the operation of the cutting tool holdingmeans which has just been describedwill now be set forth; Assuming thattheparts are in the position shown inFig, 1 and theiram H is ready to commence its downward or cutting stroke, it will benoted that the rocker plate 45 has been rocked andzthe plunger 4| of. the. valve mechanism is fully extended and theplunger 42 thereof depressed, wherefore pneumatic pressure is being admittedtothe cylinder 30 to the right of the piston and is being vvented from said cylinder at the left side of the piston 3| and said piston hasbeen movedinwardly of the'cylinder to slide the member 2| inwardly to its cutting or activepositionh At thistime thelock bolt 49 is.

projected and the member 2| is positively held thereby against outward movement. The ram. ll descends in its cutting stroke and the cutting tools 26, 21, and28 start cutting a slot l4 in the innerperiphery of the rings [3, it being understood that the work table with the rings thereon has been suitably indexed to position the. rings for the cutting-of suchzslot I4. As soon as the ram all has moved downwardly sufficiently far to free the pin 46 from the cam' surface of the cam plate 43, therockerplate 45 is partially rocked by the outward movement of the plunger 42 but not sufii'cientlyfar to admit pneumatic pressureto the left hand end of the cylinder 36. .The ram continues itsldownward or cutting stroke and the cutting tools carried byithe member 2! cut the groove l4 for aportion of its total depth. Near the end of the. downward stroke of the ram the 9 rod 5| contacts .the work supporting table and is pushed upwardly to move the bolt 49 into'the casing-.48 and free the member 2| for rearward movement to inactiveposition. Simultaneously with the completion'of the cutting stroke the pin 41 of the rocker plate 45 has been rocked by the camsurfaceof the cam plate 44 in a clockwise direction to depress the pin 4| and allowthe pin 420i theswitch mechanism 39 to comeout .to

fully extended 1 position, whereupon. pneumatic pressure is admitted to the cylinder 30 to the left of :the piston 31 and vented from the cylinder at the right ,of saidpiston and the piston is moved by'said pneumatic pressure toward the right end of the cylinder with a resultant right hand movement being imparted to the member 2| and con sequently a movement of the cutting tools to a position wherein they do not contact the inner periphery of the rings l3.

.The'vertical slotter is-provided, as previously 7 explained, with mechanism for reversing the direction of movement of the ram ll after it is moved predetermined distancesin opposite directions and therefore as soon as the cutting stroke of the tools is completed'the ram commences its upward 'or idle movement with the member 2| and-the cutting tools carried thereby in the inactive position shown-in Fig. 3. During this upnor-will the latter be damaged by-the upward movement :of the 1 tools.

next'cuttingstroke' will take a deeper cut in form'- ing the slot [4. v

After. .the ram H has moved'upwa'rdly and the I member 2 l' is elevated above the work the pin 46 of the rocker plate engages the cam surface of the cam plate 43 and rocks said rocker plate in "an anti-clockwise direction to depress 'the plunger 420i the valve mechanism and to admit pressure fluid. into the cylinder 30 'at' the right of the piston .3l and cause the latter to. move, toward the leftin the cylinder until the member 2| and cutting'tools carried thereby are-againin cutting. or active'po'sition as shown in Fig. 1.

In this connection itewill be recalled that during the left handmovement 'ofthe member 21 the lower end. of the lock bolt 49 will ride ontop of said member until the member has reached its most'left hand position, at which time the lock bolt will be projected downwardly by its spring 50 and will lie in the path of movement toward the right of the plate 36 and positively hold-the member 21 against right hand movement. The upward movement of the ram i l is automatically terminated and its downward or cutting stroke initiated by mechanism wellknown in the art andagain the cutting tools-carried by thememher 2! will make a cutting pass through the work.

The sequence of operations just described will be continued until the slot l4 has been cut to full depth, after which the ram will momentarily be held in its upward position and the work table properly indexed to position the rings 13 for the cuttingof another slotl'4 while the carriagewill.

be moved rearwardly tocommence its forward or feeding movement. 1

The form of the invention just described disbination of positive means, spring means and,

gravity; In this second form of the invention the parts which are identical with the corre-' sponding parts in the first form have been given the same reference characters and need not be specifically described. 4

A block 52 is secured to'the underside of the block l2 at the lower end of the ram II and said block 52 has secured to its underside a plate 53 fromwhich depend parallel spaced legs 54,the lower righthand' corners of which are provided with recesses 54a. The tool carrying'member of this form of the iI'IVEIItiOII'COI'ISiStSQf a pair'of parallel substantiallytriangularly shaped arms 55 interconnected at their upper ends and which are pivotally connected to the legs 54, by 'means of a horizontal shaft 56 which passes through thelegs 54 and through each arm Eli-adjacent the apex thereof. The legs '54 at their upper left hand corners and at'the location where the shaft 56 passes therethrough are provided with bosses 51 which have recesses .therein adjacent their lower ends. and surrounding the shaft 56 and V which recesses house rat trap springs 58; The

V bosses'5'lare provided adjacent therecesses with During. the upward movement of the ramthe carriage on which the 9 aplurality 61 seated: in an; 01 one end of the spiings at can be afihor'ed while the other end' of said: springs" cbln be= secured to" the shaft 56 The tension: of the springs 58 canbe adjusted by anchoring the outefi endthe? in: different ones of said slots and said springs actto rock the shaft 56 a'lndthe arms of the toolcarrying member in' a? clockwise directioiu toward active or cutting position; I -He arms 55 of the tool car-tying menilfifi are intrcoii'nefcted by" a" liar 59* to which is secuid a; socket member 60" which carries a defiend-ihg; fod= Fl" that can be vertically adjusted andclam-tied in the socket and for a purpose later to He explained.

The legs 54' are provided with spaced apart spring point-s 62 that spades apart re: c e'sses" 83 fox-fined in the arms 55* to hold the" tool carrying member ineither its active or clittinld position as shown in Fig? 5;. or its inactivaornomcuttingi position as shown in 6. l ne toolcarry-i-ngr' member may have the cutting! tools- 26; 21' and 28* secured) thereinwill be Well de'rstood in the art By insane:- on siuta-bl clamp in'g screws which need not be explained herein;

The arms 55 ofthetoo'l carrying" memiier have tectangular' bar 64 extending? between and st cured to their lower edges and: projecting later ally therefrom and: said bat curnee atone 01 its outer ends a; roller 65-:- Whn the tool carrying memberis in: cutting. 0'1 active: position the bar 64 has its projecting: ends located the recesses 54a er: the regs- 54. I justabl'e' screws smthat engage the legs 54* and limit the ddwnward' movement o'f the tool catty ing: member.

support It of the: vefitietii slotter has one: eTrrh 66 ofanangle balf Venn-calm adEiusfIabI-y cured thereto by means: of seeming: mitts which: sass" through elongated slots: iterated in s'aid arm.

weirdly fil oiiebtihg arifi 61 has s'eiiid thitki merits-16 er ehu a'plate ss wnicn extend ar allel to the age 54 Ah L-sl'ialidarfglb 1561 69 has: vei'tib'al fidr ifi'dri adiiis'ifabW seoiii 'efl to 'theplat'e 6 8' While its loviie'i fi' eiid is": attached to" the lower end ofaififiacih strap T0; the end of whichiscbhne'dted to the plate $8. The under edge of the bar F9 at he rower free end: thereof is prbvided wan a or eating portion 1 that cooperates undelf c'e'z onditions late? to he explained with the rouer' 65.

In Fi 5 the" parts are fl'l'ustr ate'd ih-rliitionship they have during the downward or dutting stroke" of theranf I. I and at vfl-iicl'i tlni'e the too carrying member is'in its dewnw cutting position agnd i's nerd ther ein By t-lie iewer spring points 62 o'f the legs 54?, an 'a' isb b'y' the action of the springsssa we r zany the-cutting" thrust on the cutting tb'ojls'z" 'pne pefts are soar ra'ng'ed that near the ehd of-thedtiwnwarfd' 0'1 ciitting strbk'eo'ftherain H themu erminutely gages the Work su'pfioltin'g" table arm the" addl nonai dbwnwardmdvementf drth ranr Fl? causes the 1:001 carrying memter'wrockwith ute shift 55* m an anti-c emise" direenbn against the as; non of the springs 58 arm the spring at. The tom-carry figi'm'efiibefistli'usrbbkd frb'rii' its active or cutting-l position to it's" inabt ive" 0 1 nun cutting position wherein the uteei sprmg po'i'ritE t2 engage in the. eer: recesses (53 of t e' 55and'hold-thetoolc'aiz ryiiifiieinrietfinitscked or elevated position and against the action of the-springs: 58;- Asthe ram-moves upwardly duting its-id1estmke the tools are completely dis- Ea'ch end of the bar carries ad: 7

inns

the rain has lfiiwd 5; be unneees'sary herein to" explain in detailthe the springs and gravity torook-theto01 oar-ryi-ngf memberto active or cutting position-.-

Fronitheioregoingdescriptiqn it'wil1- be clear- 1y evident thatin-bothforms of the inventionthe cutting tools are completely disengaged from the W01 i; prior to the commencementqf theupward oi idlestroizes' (ii the ramand; therefore, said tools" and the work are not in-jured pr worn as the Work-during. theidle strokes of the ram. In

Both erms: ofthe invention the tool carrying member: isautomatically moved from itsputting or' aqtive position into its-non-cutting or inactive position-op-vioe versa'atthepropet times near; the end (it the rafms] movement in opposite direca ti'o'n'sl; It willaiso-ha've been noted-that the points at which suchmovement ofthe toot carrying member ocour pan be varied sinoeprovision is Ina'de for adjustingthe elements that'bri-ng' about these movements of the too carrying member.

Theuse o-t thenoveland improved toolacarrying m eans'embodying thepresent invention incr-e ases the] 65 0fthe cuttingtools, eliminates frequent reg r-inding thereof: and: obviates likelihoodotinju 1 ingthe-'work-.- 'I hisinoreases'the acoupacy and efifioiency o f operatiom ofthe vertical siotten orother' similar machine tool equipped witha: too-1 c-an ying means-embodyingthepresent invent-ion: Although several embodiments:of the invention have been illustrated and described-herein i-t-W-ill be understood: that various modifications and adaptations thereof-- may' occur vvithi-n'the scope Oi the appended claims- Having thus describedmy invention, I claimv It: Ina maehinegtooi ofthetype havinga suppor tga-reciprocable ram slidable on-said-support and'adaptedto'carry a; cutting too i awork table, and means for reciproeatingsaid-ram to-mpve the cutting tool earriedthereby relative to thework onsaid A table with aputting: stroke inone 1 direction and an idle stroke in-the opposite directions 11 holding means for the cutting tool com rising-a tool carrying member supported by;said ram -to moverelative thereto from an inactive position wherein the tool will be disengaged from the work during the idle stroke to an active position where- .in the tool will engage the work with a cutting,

action during the cutting stroke, means for auto-- matically moving said member to active position at the end of the idle stroke, separate means acting to hold said member in said active'position during the cutting stroke, and means controlled by the movement of the ram and acting positively substantially at the end of the cutting stroke-to release said separate means and free said member for movement from its active positionto its inactive position. i v

2. In a machine tool of the type having a support, a reciprocable ram slidable on said support and adapted to carry a cutting tool, a

work table, and means for reciprocating said ram to move the .cutting tool carried thereby; relative to the work on said table with a cuttingstroke in one direction and an idle stroke in the opposite direction; holding means for the cutting tool comprising a tool carrying member. sup-. ported by said ram to move relative thereto from an inactive position wherein the tool will be disengaged from the work duringthe idle stroke'to an active position wherein the tool will engage the work with a cutting action during the cutting stroke, means for automatically moving said member to said active position'at the end of the idle stroke, separate means acting to hold said member in said active position during the cutting stroke, and means carried, by said ram and operating with said table substantially at the end of the cutting stroke to release said separate means and free said member for movement from its active position to its inactive position.

3. In a machine tool of the type having a support, a reciprocable ram slidable on said support and adapted to carry a cutting tool, a' work table; and means for'reciprocating said ram to move the cutting tool carried thereby relative to the work on said table with a cutting stroke in one direction and an idle stroke in the'opposite-direction; holding means for the cutting tool com: prising a. tool carrying member supported by said ram'to move relative thereto from an inactive position wherein the tool will be disengaged from the work during the idle stroke to an active position wherein the tool will engagethe work with a cutting action during the cutting stroke, power means for moving said member to said 'active position at the end of the idle stroke and to said inactive position at the end of the cutting stroke, locking means for positively locking said member in said active position during the cutting stroke, and means controlled by the move ment of the ram and acting automatically'sub stantially at the end of the cutting stroke for releasing said locking means to free said member 'for movement from its active position to its inactive position. i

4. A machine tool as defined in claim 3 and wherein means is provided for holding said looking means in retracted position during the idle stroke.

5. In a machine tool ofthis type having a support, a reciprocable ram slidable on said support and adapted to carry a cutting tool, a work table, and means for reciprocating said ram to move the cutting tool carried thereby relative to the work on said table with a cutting'stroke in one direction and an idle stroke in the opposite irection; holding means for the cutting tool comprising 'a' tool carrying member supported by said-ram to move relative thereto from an inactive position whereinthe tool will'be disengaged from the work during the idle stroke to an active position wherein the'tool will engage the work with a cutting actionduring the cutting stroke, power means controlled by the movements of said ram for movingsaid member to said active position :at the end of the idle stroke and to said inactive position at the end of the cutting stroke, a normally'e'xtended lockbolt adapted to positively'h'old said member against movement from said active position to said inactive position, and means controlled by the movement of the ram and acting substantially at the end of the cutting stroke to retract said normally extended lock bolt and free said'member for movement from active position to inactive position;

6. A machine tool as definedin claim 5 and wherein the'means controlled by the movement of the ram comprises an element carried by the ram and cooperating with the work table substantially at the end of the cutting stroke to positively retract said lock bolt and free said member for movement from active to inactive position, while said'member is provided with a portion acting to hold said lock bolt retracted when said member is'in inactive position.

'7. In a machine tool of the type having a support, a reciprocable ram slidable on said support and adapted to carry a cutting tool, a work table, and means for reciprocating said ram to move the cutting tool carriedthereby relative to the work on said table with a cutting stroke in one direc-. tion and an idle stroke in the opposite direction; holdingmeans for the cutting tool comprising a tool carrying-member pivotally supported by said ram to swing relative thereto from an inactive position wherein the tool .Will be disengaged from the Workduring the idle stroke to an active position wherein the tool'will engage the work with a cutting action during the cutting stroke, means for causing said member to automatically swing to said active position at the end of the idle stroke, separate means acting to hold said mem-' her in said active position during the cutting stroke, and means controlled by the movement of the ram and acting positively substantially at theend of the cutting'stroke to release said separate means and free said member for swinging movement from its active position to its inactive position. I I I ;8. A machinetoolas defined in claim 7 and wherein said memberis provided withan element cooperatingwith said table substantially at the end of the cuttingstroke to release saidseparate meansand positively swing saidmember from active to inactive-position. Y

.9.. In a machine tool of the type having asupport, a, reciprocableram slidable 'on said support andadaptedto carry a cutting tool, a work table,

and meansfor reciprocating said ram to move 7 the," cutting tool carried thereby relative to the Work on said table with a, cutting stroke in one direction and an idle stroke in the opposite direction; holding means for the cutting tool comprising a tool carrying member pivotally sup ported by said ramto swing relative thereto from an inactive position wherein the tool will be disengaged from the workduring the idle stroke to an active position wherein the tool will engage the workjwith .a cutting action during the cutting stroke,'m eans for urging'said member toward said active] position, separate means acting to,

hold said member in said active position during the cutting stroke, means controlled by the movement of the ram and acting positively substantially at the end of the cutting stroke to release said separate means and move said member from active to inactive position, a second separate means acting to hold said member in said inactive position during the idle stroke, and means controlled by the movement of the ram and act ing positively substantially at the end of the idle stroke to release said second separate means and free said member for movement from inactive position to active position.

10. A machine tool as defined in claim 9 and wherein the means which acts to release the first mentioned separate means and to move said member from active to inactive position includes an element carried by said member and cooperating with the work table substantially at the end of the cutting stroke while the means which acts to release said second separate means at the end of the idle stroke includes cooperating elements carried by said member and by said support.

JOHN A. BACKSTROM.

REFERENCES CITED The following references are of record in the file of this patent:

Number FOREIGN PATENTS Country Date Germany Jan. 25, 1886 Great Britain Jan. 5, 1922 Great Britain June 5, 1930 

